Cod sursa(job #2068589)

Utilizator tanyafTanya Foransbergher tanyaf Data 18 noiembrie 2017 09:30:19
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.97 kb
#include <fstream>
#include <bits/stdc++.h>
using namespace std;
ifstream f ("evaluare.in");
ofstream g ("evaluare.out");
char s[100005],*p;
int eval();
int termen ();
int factor();
int main()
{
    f.getline(s,100005);
    p=s;
    g<<eval();
    return 0;
}
int eval()
{
    int r;
    r=termen();
    while(*p=='+'||*p=='-')
        if(*p=='+')
        {
            ++p;
            r+=termen();
        }
        else {++p;r-=termen(); }
    return r;
}
int termen()
{
    int r;
    r=factor();
    while(*p=='*'||*p=='/')
        if(*p=='*')
        {
            ++p;
            r*=factor();
        }
        else
        {
            ++p;
            r/=factor();
        }
    return r;
}
int factor ()
{
    int r;
    r=0;
    if(*p=='(')
    {
        ++p;
        r=eval();
        ++p;
    }
    else while(*p>='0'&&*p<='9')
        {
            r=r*10+(int)*p-'0';
            ++p;
        }
    return r;
}